meeting-assistant/openspec/changes/archive/2026-05-28-append-file-write-tools-by-default/proposal.md

Change: Append file-write tools by default

Why

Agent-facing file write tools currently replace whole files when no line arguments are supplied. This is risky because agents often intend to add context and can accidentally overwrite project knowledge, assistant context, or local workflow rules.

What Changes

• Make summary-agent assistant context and project file writes append by default.
• Add an optional replace_file boolean to explicitly request whole-file replacement.
• Make workflow rules editor writes append by default and require replace_file for whole-file replacement.
• Keep line-range replacement and insertion behavior unchanged.

Impact

• Reduces accidental destructive writes from summarizer and rules editor agents.
• Existing callers that intentionally replace whole files must pass replace_file: true.